falconman

Ams-oil recomends a 25,000 mile change period on their engine oil. has anyone done this? It seems pretty stupid to wait 25,000 miles, but would like to know if it works.What is the maximum you would wait to change it?

Thanks

MotorMouth

Mobile Delvac that we run in our trucks go 100000 between oil changes. Today's oils are a lot different than they used to be. I never change my oil before 6000 miles. 3000 is a waste of money. ONLY in the USA is it recommend to change it every 3000. The same cars overseas is 6000 or more.

Jaxom

Some of the manufacturers are recommending as much as 10-15k between synthetic oil changes on new cars. I don't think I'd stretch it to 25, but with a tight engine and good oil you can certainly go FAR longer than the old 3k rule.

Stevolwevol

iTrader: (1)

Where overseas do they recommend 6000 mile oci?

Damon

High quality synthetic oils are made from a base stock that is unlikely to EVER chemically break down. In short, you'll never wear it out.

HOWEVER.... oil still gets dirty (much less quickly in modern EFI engines than old carbureted setups) and the additive packages they put in the oil like anti-corrosion chemicals and such DO GET USED UP OVER TIME. Hence, you still need to change the oil from time to time, although much less frequently under many conditions.

Many big rigs and other applications often use more sophisticated filtration systems than your car's engine. Additionally, they have the oil chemically tested on a regular basis and add back in only the chemical additives that are needed to bring the oil back up to snuff. In essence, they almost never need to pull the drain plug and do what you would recognize as an "oil change".

hotrodln

GM has an oil life monitor in my 08 CTS.....if i listened to THAT, i'd be leaving my oil in for 10 to 15k.....well i guess they were starting to have too many engine problems, so i just got a recall notice.....if i bring the car in , they will recalibrate it ....now to HALF of what it was......i run synthetic and change it at 5 k anyway.....but i'm sure GM is recalling other cars for the same thing........somebody really goofed on that one.....

hartman

iTrader: (6)

amsoil is some of the best out there. If you run their oil with their filter they guarantee it for 25,000 miles. Ive never heard anything bad or had any problems with amsoil.

cIaRmOaCrZo

yeah iv been sceptical about amzoil..personally i thaught it was just a bunch of bologna lol. but since iv never personally used it, i cannot be knocking it. but until i see some hard proof (not hear say), then i would feel more comfortable switching from mobil 1. (which i stand by big time due to real proof i personally experienced)

Stevolwevol

iTrader: (1)

I change my oil when it gets dirty, not when it breaks down. Even dino oil doesn't break down in 3000 miles, but it is the impurities that dirty it up.

Jaxom

I will say that I've had excellent performance from Amsoil's trans and differential fluids. I put their synthetic ATF in my T56 when I swapped it into the car (8+ years and ~150k miles ago) and it still looks fantastic when I check the level. I doubt I'll ever need to change it....the synchros will probably wear out before that fluid does.

MotorMouth

I seen an owner's manual for a Benz that was bought in Germany and then shipped over here by the GI that was the owner when he retired from the Army. In it with the conversion from KM to miles it was roughly 6000 miles. This was 16 years ago before the synthetics took off like they have now.

Stevolwevol

iTrader: (1)

Mercedez has always had a top quality car. It would be interesting to see a Chevy owner's manual in Germany.

AlkyIROC

Oil life depends a lot on driving habits. The onboard oil life indicator built into many new cars takes into account your driving habits and usage through different operating temperatures of the engine and will indicate when the oil should be replaced based on how the vehicle is driven.

The 3000 mile (5000 km) oil change interval is for normal driving habits. Stop and go and short trip city driving is considered extreme driving habits and it's recommended to change the oil at sooner intervals.

Big diesel engines can run extended intervals because of a few different factors. They have a larger oil capacity so the oil doesn't get dirty as quickly, they run larger oil filters, the engines operate at lower rpms, the highway trucks run constant speeds for long periods of time.

On a long haul highway truck, an oil change can be 20,000-25,000 km and may be done every month or 2. City trucks are usually around 10,000 km. Those highway trucks also hold 10 gallons of oil (40 liters) and the filter alone holds around a gallon. Medium duty city type trucks hold 20-30 liters of oil (5-15 gallons). Many cars still only hold around 5 quarts of oil and a small filter.

It's not that the oil breaks down or not, it's that the oil gets dirty even with a good filter and gets contaminated. A filter can't remove condensation, fuel dilution or any of the chemical contamination such as acids, or any of the metal contamination from bearing wear etc. All the filter removes is soot and dirt.

My F350 diesel holds 16 liters of oil and I still change it at 3000 miles. The engine oil also controls the fuel injectors and dirty oil can make the injectors fail. It's cheaper to change the oil and filter than a single injector.

falconman

Holy ****. how much does each change cost?

AlkyIROC

I buy oil in 5 gallon pails and I get the filters at dealer cost but changing the oil and oil/fuel filters is around $70-80. An inexpensive warranty injector is around $150 and those are getting hard to order. Regular injectors are around $300 and there's 8 of them in my engine.

That's about the same price as oil changes on my race car. I run full synthetic oil that's around $10/liter and the car holds 9 liters with the oil that's in the pan and accumulator. I run a System 1 oil filter so that just gets disassembled, cleaned and reinstalled. I change the oil in the car every spring before race season.

People whining about changing 5 quarts of oil and a filter in a street car every 3000 miles? That's pocket change. It doesn't matter if it's dyno or synthetic oil in your engine. The oil is the lifeblood of the engine and dirty oil will decrease the life of the engine. My diesel now has over 200,000 km on it and it's still going strong.

five7kid

iTrader: (14)

Been doing it AMSOIL's way since 1983.
Mobil 1 tried to imitate AMSOIL and gave up. Which has made me pretty skeptical of Mobil.

Not sure what would qualify as "hard proof" for you - standardized tests, several side-by-side field tests, millions upon millions of miles of customer use over 4 decades - if that isn't enough for you, you're probably a lost cause.

74Novaguy

I ran amsoil once in my truck. it didnt do to well it started to sludge up after about 10k miles. Also amsoil recomend 15k miles if you drive your vehicle hard. or if its turbo or supercharged. and the cost of it is just way to high. Ive seen everyday cars and cars with many mods run just fine on conventional oil. Ive seen 300k plus on a nissan that never saw anything other than 10-30 penzoil. I run castral gtx and have never had an issue, just change it every 5000 miles. Oil companys are the ones that recomend every 3000, manufactures recomend 5-7 unless its high end then there around 12-15k but they have a different oil/filtering system.

five7kid

iTrader: (14)

How many miles did it have on it before you put the AMSOIL in? What kind of maintenance did it get before that?

hartman

iTrader: (6)

agreed you cant excpect to get 15k+ the first time you put amsoil in. After a couple amsoil oil changes then you can go the 15k or 25k

74Novaguy

I had 80k miles at the time and had changed the oil every 5k and ran cleaners ever 10k (got them free at work). I ran the Amsoil engine cleaner threw it as directed by amsoil before switching to amsoil. My parts dealer also had a problem with them and he had be running it in his toyota for about 5 years.

five7kid

iTrader: (14)

Something was going on that you either were unaware of, or aren't telling us. AMSOIL does not "sludge up" engines. It might loosen up the sludge already in a sludged-up engine, but AMSOIL was not the source of sludge.

camaronewbie

It might be fine, but I can't afford to test it personally - unemployment makes buying new motors to test difficult. So I'll stick to my dino oil and 3000 mile changes.

Why would a carbed motor make dirtier oil than an EFI motor? How the fuel is introduced to the combustion chamber makes no difference on internal oiling issues and the "dirt" accumulated from an engine running.

hotrodln

carb'd engines get their oil waaaay dirtier than EFI....it's all the extra gas they waste in combustion, coupled with the inevitable leakage while it's just sitting there not running.......the oil in my 62 caddy looks like crap after a month of limited use....it's completely rebuilt and runs good.....just messes up the oil fast.........

five7kid

iTrader: (14)

Yes, carbs get crankcase oil contaminated much more than EFI. Sucking fuel into an air stream is not nearly as exact, nor is vaporization as complete, as properly tuned (even factory tune) EFI is.

Stevolwevol

iTrader: (1)

Yes, carbed engines dirty up the oil faster than injected engines, however my carbed 305 stays amazingly clean. The oil looks pretty good even after 2000 miles.

cIaRmOaCrZo

well i guess "my hard proof" isnt as extensive as you think it should be, but at my shop where i do several intake jobs, pan drops, ect.., whatever oil they use "usually junk **** we sell" and theyr engines are just freakin NASTY (some neglect, so its not full blame on oil). but iv had to scoop up sludge with my damn hands before i can even put solvants to it to clean anything out. rocker valleys have plugged up holes and black hardend crust built up all thoughout the engine. and most of these cars arent any older than 10yrs.

then i pull my 305 tpi (nothing wrong with it at all) to put in my 383. then a guy wanted to buy it without the tpi setup. so i pull the intake, and pull the pan(since it was on a stand). and that engine is SPOTLESS. and its 20+ years old and its CAST iron. i know i didnt put all 160k miles on it but i put about half that and used mobil 1 full syn from the start of my ownership. pan had NO slug. everything was just clean and beautiful.

not saying thats eveybodys experience, and i DID NOT say amzoil isnt better(it may be), just said i was SKEPTICAL to switch from something i find that WORKS for ME!!! thats all i was sayin....lost cause my ***

ASE doc

Amsoil also offers a "lifetime oil change" if you use their proprietary filtration system, which basically consists of two large filters in series. You just change the filters, can't remember the interval, and add oil to refill. I've installed this system on a few trucks.

Personally, I change my oil every 3,000mi and run Mobil 1 and WIX 1061 filter. I would consider running Amsoil but dealers are hard to find in some areas and I like being able to buy my oil in retail stores. Although the 15-50 High Performance oil I run is sometimes hard to find.

Even if I ran Amsoil, I would still change my oil at 3,000mi. It's just a thing with me.

Kevman

Oil change every 6000 miles?!
If I don't change the oil in the work van every 3000 it comes out like tar...